CH662989A5 - VALUE PAPER. - Google Patents

Abstract

The document of value is provided with a safety design extending on one portion or the whole of its surface. The entire surface of the safety design consists of juxtaposed groups of segments of raised parallel lines of two different heights forming high reliefs and low reliefs portions. The segments of two adjacent groups are parallel to two predetermined directions, preferably substantially perpendicular. The assembly of segments parallel to one of the directions and consisting of high reliefs on the whole or part of their length define a transitory image visible when the document is illuminated or observed parallel to a direction perpendicular to said segments and forming an acute angle with the plane of the document of value. A second transitory image is formed in a similar manner by high relief segments parallel to the other direction. The low raised segments or segment fractions constitute the background of the safety design. All the raised segments and the gaps left between the segments have preferably the same color.

Description

The present invention relates to a security paper having a security design, in particular a bank note, or fiduciary paper, extending over part or all of said security paper comprising a background and two transient images.

In order to avoid the issuance of false security papers, particularly banknotes, different printing methods were used and security papers were notably provided with security drawings made up of thin lines of different colors forming complex figures so that reproduction by photographic means is difficult. However, the evolution of reproduction techniques has enabled counterfeiters to overcome this difficulty, at least in certain cases. Another solution has been the manufacture of valuable papers, at least part of the surface of which comprises relief lines produced by the so-called intaglio process. Several variants have been proposed on the basis of this process. In particular, it has been proposed to produce a transient image formed by parallel raised lines. According to a variant, the transient image is detectable only through an appropriate transparent screen, illuminating the value paper with an appropriate light. In another case, the color of the sides of raised lines varies along its length or from one side to the other, so that by observing the banknote from two different angles, we see two different images appear depending on whether one or the other. the other side of raised lines is hidden Finally, in another case, the lines in relief have a uniform color contrasting with that of the paper (the spaces between the lines) so that the image formed by these lines in relief only appears when looking at the drawing. at a relatively small acute angle and parallel to a plane perpendicular to these lines, which in this case hide the spaces between them and reveal a uniformly colored image. This image is difficult to detect if we look at the drawing in a direction perpendicular to its plane because the contrast of the colors between the lines and the inter-lines decomposes the image.

These solutions have contributed to making it difficult if not impossible to manufacture valuable false papers because no photographic device can produce a three-dimensional reproduction. However, the variants cited first have the disadvantage of requiring an additional device (screen, lens, special light lamp, etc.) to carry out the authenticity check and therefore to make it almost impossible during use. stock of value papers. As for the last two variants, they require very high precision for the production of transient images in order to obtain a perfect register of colors. On the other hand, the viewing angle is relatively small, of the order of 15 ° to 20 ° relative to the plane of the paper, which makes checking a large number of valuable papers tedious.

The object of the present invention is to remedy these drawbacks by allowing a security drawing to be produced on one hand on a valuable paper using the intaglio process, without causing any color contrast to occur. on the other hand the safety pattern can easily be detected by a non-specialized person without using auxiliary means such as blade, screen, lenses, etc., and at a relatively large acute angle.

The security design according to the invention is characterized in that the entire surface of the security design is made up of juxtaposed groups of segments of parallel lines in relief of two different heights, forming high and low reliefs, s' alternately extending in two different predetermined directions so that the segments of a group are not parallel to those of an adjacent group, that the periphery of each group defines a planar geometric figure which is the same for all groups of segments parallel to the same direction and is completed with the peripheries of the adjacent groups to compose the surface of the drawing, that a part of all the segments present on the whole or a fraction of their length said high relief, that the first transient image is formed by the high reliefs of the segments parallel to the first direction and belonging to several groups, while the second transient image is formed by the high reliefs of the segments parallel to the second direction and also belonging to several groups, that at least part of the segments forming the two images belongs to adjacent groups, that an image appears when it is illuminated by rays luminous at an acute angle with the plane of the drawing and parallel to a plane at least approximately perpendicular to the direction in which the segments so forming the image are parallel or when the drawing is viewed at an acute angle and parallel to at least one plane approximately perpendicular to the direction in which the segments forming the image are parallel, that the segments or the fractions of the segments having the low relief form with the spaces between segments the background of said security design.

The advantages of the subject of the invention are as follows: the safety design is composed of segments of parallel raised lines arranged in juxtaposed groups which are easily obtained by intaglio printing and without being obliged to have recourse to 60 meticulous adjustments to respect the color register, the entire safety drawing, raised segments and inter-segments can be the same color. The authenticity check can be done by any user either by illuminating the drawing with natural light or a common electric lamp, or more simply by looking at it at an acute angle and parallel to a plane perpendicular to the lines. in relief forming one of the images. A rotation of the paper value of an angle approximately equal to the angle between the two predetermined directions, to which are respec parallel

the segments of two adjacent groups, brings up the second image.

The fact that an image appears when the drawing is illuminated at an acute angle and parallel to a plane at least approximately perpendicular to the raised segments making up the image is due to the fact that the segments whose height is greater than that of the segments composing the background of the drawing, or rather the groups of segments, appear to have a darker color because of the shadow cast by the segments on top of each other and the fact that the density of the segments seems to increase when observed in a direction perpendicular and at an acute angle with respect to their support. It is obvious that, to obtain these results, it is sufficient that the lighting or observation angle is simply less than 90 °.

By observing the paper perpendicular to its plane, no image can be distinguished, all the more so since the groups comprising the segments making up the two images are at least for part of them adjacent; we can therefore say that the images are partially mixed.

According to a preferred variant, the two directions to which the raised segments are parallel are perpendicular and the geometric figure determined by the periphery of a group of segments is a rectangle, in particular squares.

The invention will be described in more detail using the attached drawing.

Figure 1 is a perspective view of a safety drawing showing a first image.

Figure 2 is a view similar to that of Figure 1 showing a second image.

Figure 3 is a sectional view of an enlarged portion of a value paper showing the various elements in relief.

Figure 4 is a greatly enlarged perspective view of part of a safety drawing.

Figure 5 shows a bank note with the security design.

Figure 6 is a greatly enlarged plan view of part of the safety drawing.

The safety drawing S shown in FIGS. 1 and 2 of a paper P value is made up of raised straight lines arranged in groups 1.2 juxtaposed. Figure 6 shows some of these groups on a large scale. The segments of two adjacent groups 1, 2 are parallel to two perpendicular directions. The raised segments are shown in black, but in reality the color of the raised segments and the space between two segments is the same. There may be a difference between the raised segments and the space between two raised segments if the paper backing is of a color contrasting with the color of the printing ink of the security drawing, due to the difference of the thickness of the ink layer between a raised segment and the space between two segments, as will be seen below.

In general and subject to the above-mentioned remark, the safety design appears, observed perpendicular to its plane, as having a uniform color. The figures delimited by the ends of the segments and the extreme segments of each group 1, 2 form a square. However, any other figure can be produced provided that the peripheries of two adjacent groups are combined, so that the entire background of the drawing is continuously covered.

By illuminating or observing the drawing at an acute angle and parallel to direction D which is at least approximately

662,989

perpendicular to one of the directions to which the segments are parallel, we see a first image appear which is an A, this image is formed by segments and fractions of segments in relief of a height greater than that of the other segments, respectively fractions of segments, and perpendicular to the direction D. If we turn the P value paper 90th, we see the second image appear which in this case is a Z (the letters A, Z on the periphery of the drawing constitute only bridges for understanding the figures). This second image is formed in the same way as the previous one, but by segments perpendicular to the segments of the previous image.

Of course, if the two predetermined directions to which the segment is parallel are not perpendicular, then the rotation of the P value paper must be made at an angle equal to the angle of these two directions.

In Figure 3, we can see in section the different elements of the safety drawing. The P value paper is covered with a layer of ink 3 having three different levels. The lowest level ni is the level between the raised segments. Then there is the level n2 which is that of the low relief segments. The levels ni and n2 form the background of the security design. The level n3 is that of the segments or fractions of segments in high relief making up one or the other of the transient images.

By way of example, the segments 4 and 5 belonging to two adjacent groups are segments or fractions of segments in low relief and therefore belong to the background of the safety drawing. The segments 4 are perpendicular to the plane of Figure 3 and the segment 5 parallel to this plane. The segment 7 which is parallel to the segments 4 is a segment whose upper part is along its entire length or only a fraction at the highest level n3 and contributes to the composition of one of the transient images. The top of segment 6, which lines up with segment 5, is on two levels. A first part is at level n3, therefore in high relief, and contributes to the composition of the other transient image and two other parts are at level n2, therefore in low relief, and form part of the background of the drawing.

The detail illustrated in enlargement in Figure 4 also shows the construction of the safety drawing. The groups with segments parallel to the front edge F of the value paper P are all part of the background of the drawing, while the segments perpendicular to the edge F belonging to the other groups include a transparent image. The segment 8 has an upper part which is at level n3 and another which is at level n2. The segments belonging to the same group as segment 8 also have their upper part at level n3. Segment 9 and those of its group also have two different levels spanning unequal lengths; the same is true for segment 10. The other segments illustrated parallel to segment 10 are of level n3. All the segments or parts of segments of level n3 contribute to the composition of an image which can be observed if we illuminate the drawing or if we look at it in a direction parallel to D '.

The security design can occupy either part of a valuable paper, as illustrated in Figure 5, or the entire surface of the paper.

The licensee produced a security drawing on a bank note using the intaglio process using the following sizes for the three levels relative to the surface of the value paper:

or

= 0.03

mm n2

= 0.07

mm n3

= 0.14

mm

3

5

10

15

20

25

30

35

40

45

50

55

R

3 sheets of drawings

Claims (4)

662989 1. Value paper having a security design extending over part or all of said security paper, comprising a background and at least two transient images, characterized in that the entire surface of the security design is composed of groups juxtaposed with segments of parallel lines in relief of two different heights, forming high and low reliefs, extending alternately in two different predetermined directions so that the segments of a group are not parallel to those of an adjacent group, that the periphery of each group defines a plane geometrical figure which is the same for all groups of segments parallel to the same direction and is completed with the peripheries of adjacent groups to compose the surface of the drawing, that only part of all the segments present over all or a fraction of their length said high relief, that the first transient image is formed by the high reliefs of the segments parallel the first direction and belonging to several groups, while the second transient image is formed by the high reliefs of the segments parallel to the second direction and also belonging to several groups, that at least part of the segments forming the two images belongs to adjacent groups, that an image appears when illuminated by light rays making an acute angle with the plane of the drawing and parallel to a plane at least approximately perpendicular to the direction in which the segments forming the image are parallel or when the drawing is viewed at an acute angle and parallel to a plane at least approximately perpendicular to the direction in which the segments forming the image are parallel, which the segments or the fractions of the segments having the low relief form with the spaces between segments the background of said security drawing. 2. Value paper according to claim 1, characterized in that the planar geometric figures defined by the peripheries of the groups of segments are rectangles, in particular squares. 2 3. Value paper according to claim 1 or 2, characterized in that the two predetermined directions are perpendicular. 4. Value paper according to one of claims 1 to 3, characterized in that the entire security design, raised segments and space between segments, is the same color.